What purpose does fuel wood serve

it insures that people can boil water and cook food

Fuelwood refers to various forms of wood that are used as fuel for cooking, heating or to drive steam-powered engines or turbines for electricity generation.

Fuelwood remains the primary source of fuel for much of the world’s population. The use of wood as a fuel source is older than recorded history, and is believed to be one of the primary innovations that allowed for development of civilization as we know it. Unfortunately, overconsumption of fuelwood has led to deforestation and habitat loss, and unless wood is burned in efficient furnaces, its combustion contributes to emissions. Fuelwood can include firewood, charcoal, pelleted sawdust and wood chips.